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US4775972A Expired / Lapsed US ⏱️ 0.0 years remaining

Optical fiber communication for local area networks with frequency-division-multiplexing

Assignee: ITT Corp DEFENSE COMMUNICATIONS DIVISION
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Filing: 1985-05-10
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Granted: 1988-10-04
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Expires: 2005-05-10
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Abstract

Abstract A method and associated system for providing multi-channel transmission of digital and broadband video information in optical fiber communication for local area networks through frequency-division-multiplexing, comprising the steps of generating a plurality of closely spaced optical carrier wave pairs with the optical carrier waves within each optical carrier wave pair having a predetermined separation frequency between one another, assigning each of the plurality of optical carrier wave pairs to a predetermined frequency slot and optically combining the plurality of optical carrier wave pairs to provide a multiplexed optical output wave. Advantageously, in addition to direct detection the plurality of optical carrier wave pairs may be detected by opto-electronic heterodyne detection and/or incoherent optical-heterodyne detection to electronically recover the optical carrier wave pairs.

Inventors

  • 👤 Charles C. Ih
  • 👤 Charles K. Kao

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 01:24
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/50; H04B10/572

Claims Analysis

Total Claims: 41
Claim 1
Independent Claim 108 words
A method of providing multi-channel transmission of digital and broadband video information in an optical fiber local area network through frequency-division-multiplexing, comprising the steps of: generating a plurality of closely spaced optical carrier wave pairs with the optical carrier waves within each optical carrier wave pair having a predetermined separation frequency between one another, the separation frequency between the two optical carriers within each optical carrier wave pair being different for each optical carrier wave pair; assigning each of the plurality of optical carrier wave pairs to a predetermined frequency slot; and optically combining the plurality of optical carrier wave pairs to provide a multiplexed optical output wave.
Claim 2
Independent Claim 108 words
A method of providing multi-channel transmission of digital and broadband video information in an optical fiber local area network through frequency-division-multiplexing, comprising the steps of: generating a plurality of closely spaced optical carrier wave pairs with the optical carrier waves within each optical carrier wave pair having a predetermined separation frequency between one another, the separation frequency between the two optical carriers within each optical carrier wave pair being different for each optical carrier wave pair; assigning each of the plurality of optical carrier wave pairs to a predetermined frequency slot; and optically combining the plurality of optical carrier wave pairs to provide a multiplexed optical output wave.
Claim 3
Dependent Claim 29 words
The method recited in claim 1, wherein: the frequency separation between the two optical carriers within each optical carrier wave pair can vary up to several tens of GHz.
Claim 4
Dependent Claim 34 words
The method recited in claim 1, wherein: the frequency slots are assigned so that the separation between adjacent optical carrier wave pairs is on the order of at least 300 GHz to 600 GHz.
Claim 5
Dependent Claim 22 words
The method recited in claim 1, wherein: each of the plurality of optical carrier wave pairs is generated independently of one another.
Claim 6
Dependent Claim 27 words
The method recited in claim 1, wherein: the assigning step is accomplished by operating a plurality of transmitting lasers at slightly different frequencies to avoid spectral overlap.
Claim 7
Dependent Claim 52 words
The method recited in claim 5, wherein: the step of generating the optical carrier wave pairs is accomplished by a plurality of standing-wave-surface-acoustic-wave transducers operating at different frequencies which are positioned to deflect the frequencies of output laser beams from the transmitting lasers to provide the plurality of optical carrier wave pairs.
Claim 8
Dependent Claim 17 words
The method recited in claim 1, including the step of: optically amplifying the multiplexed optical output wave.
Claim 9
Dependent Claim 19 words
The method recited in claim 1, wherein: the optical carrier wave pairs are used for simultaneous digital information transmission.
Claim 10
Dependent Claim 19 words
The method recited in claim 1, wherein: the optical carrier wave pairs are used for simultaneous analog information transmission.
Claim 11
Dependent Claim 21 words
The method recited in claim 1, wherein: the optical carrier wave pairs are used for simultaneous digital and analog information transmission.
Claim 12
Independent Claim 97 words
A method of providing multi-channel transmission of digital and broadband video information in an optical fiber local area network through frequency-division-multiplexing, comprising the steps of: generating a plurality of closely spaced optical carrier wave pairs with the optical carrier waves within each optical carrier wave pair having a predetermined separation frequency between one another; assigning each of the plurality of optical carrier wave pairs to a predetermined frequency slot; opto-electronic heterodyne detecting the frequencies of the optical carrier wave pairs; and optically combining the plurality of optical carrier wave pairs to provide a multiplexed optical output wave.
Claim 13
Independent Claim 97 words
A method of providing multi-channel transmission of digital and broadband video information in an optical fiber local area network through frequency-division-multiplexing, comprising the steps of: generating a plurality of closely spaced optical carrier wave pairs with the optical carrier waves within each optical carrier wave pair having a predetermined separation frequency between one another; assigning each of the plurality of optical carrier wave pairs to a predetermined frequency slot; opto-electronic heterodyne detecting the frequencies of the optical carrier wave pairs; and optically combining the plurality of optical carrier wave pairs to provide a multiplexed optical output wave.
Claim 14
Dependent Claim 44 words
The method recited in claim 11, wherein the opto-electronic heterodyne detecting step includes: superimposing a high frequency voltage on a DC bias voltage of an avalanche photo-diode to provide beat frequencies between the plurality of optical carrier wave pairs and the high frequency voltage.
Claim 15
Dependent Claim 53 words
The method recited in claim 11, wherein the opto-electronic heterodyne detecting step includes: generating a local optical carrier wave pair; and combining the incoming optical carrier wave pairs with the local optical carrier wave pair to generate beat frequencies between the incoming optical carrier wave pairs and the local optical carrier wave pair.
Claim 16
Independent Claim 167 words
A method for providing multi-channel transmission of digital and broadband video information in an optical fiber local area network through frequency-division-multiplexing, comprising the steps of: independently generating a plurality of closely spaced optical carrier wave pairs with the optical carrier waves within each optical carrier wave pair having a predetermined separation wavelength between one another of between a fraction of a nanometer up to approximately one nanometer and in which the wavelength separation between the two optical carriers within each optical carrier wave pair is different for each optical carrier wave pair; assigning each of the plurality of optical carrier wave pairs to a predetermined frequency slot; optically combining the plurality of optical carrier wave pairs to provide a multiplexed output wave; and the step of generating the optical carrier wave pairs is accomplished by a plurality of standing-wave-surface-acoustic-wave transducers operating at different frequencies which are positioned to deflect the frequencies of output laser beams from transmitting lasers to provide the plurality of optical carrier wave pairs.
Claim 17
Independent Claim 167 words
A method for providing multi-channel transmission of digital and broadband video information in an optical fiber local area network through frequency-division-multiplexing, comprising the steps of: independently generating a plurality of closely spaced optical carrier wave pairs with the optical carrier waves within each optical carrier wave pair having a predetermined separation wavelength between one another of between a fraction of a nanometer up to approximately one nanometer and in which the wavelength separation between the two optical carriers within each optical carrier wave pair is different for each optical carrier wave pair; assigning each of the plurality of optical carrier wave pairs to a predetermined frequency slot; optically combining the plurality of optical carrier wave pairs to provide a multiplexed output wave; and the step of generating the optical carrier wave pairs is accomplished by a plurality of standing-wave-surface-acoustic-wave transducers operating at different frequencies which are positioned to deflect the frequencies of output laser beams from transmitting lasers to provide the plurality of optical carrier wave pairs.
Claim 18
Dependent Claim 21 words
The method recited in claim 14, including the step of: opto-electronic heterodyne detecting the frequencies of the optical carrier wave pairs.
Claim 19
Dependent Claim 44 words
The method recited in claim 15 wherein the opto-electronic heterodyne detecting step includes: superimposing a high frequency voltage on a DC bias voltage of an avalanche photo-diode to provide beat frequencies between the plurality of optical carrier wave pairs and the high frequency voltage.
Claim 20
Dependent Claim 51 words
The method recited in claim 15 wherein the opto-electronic heterodyne detecting step includes: generating a local optical carrier wave pair; and combining the incoming optical carrier wave pairs with local optical wave pair to generate beat frequencies between the incoming optical carrier wave pairs and the local optical carrier wave pair.
Claim 21
Dependent Claim 178 words
A frequency-division-multiplexing system for providing an optical fiber local area network (LAN) with multi-channel transmission of digital and broadband video information, comprising: means for generating a plurality of closely spaced optical carrier wave pairs with the optical carrier waves within each optical carrier wave pair having a predetermined separation frequency between one another; means for assigning each of the plurality of optical carrier wave pairs to a predetermined frequency slot; means for optically combining the plurality of optical carrier wave pairs to provide a multiplexed optical output wave; means for opto-electronic heterodyne detecting the frequency of the optical carrier wave pairs, said opto-electronic heterodyne detecting means including an avalanche photo-diode, a DC voltage source coupled to said avalanche photo-diode to supply a DC bias voltage thereto, means for superimposing a high frequency voltage on the DC bias voltage to provide beat frequencies between the plurality of optical carrier wave pairs and the high frequency voltage when the optical carrier wave pairs are detected by said avalanche photo-diode; and optical amplifying means optically coupled to said optical combining means.
Claim 22
Dependent Claim 178 words
A frequency-division-multiplexing system for providing an optical fiber local area network (LAN) with multi-channel transmission of digital and broadband video information, comprising: means for generating a plurality of closely spaced optical carrier wave pairs with the optical carrier waves within each optical carrier wave pair having a predetermined separation frequency between one another; means for assigning each of the plurality of optical carrier wave pairs to a predetermined frequency slot; means for optically combining the plurality of optical carrier wave pairs to provide a multiplexed optical output wave; means for opto-electronic heterodyne detecting the frequency of the optical carrier wave pairs, said opto-electronic heterodyne detecting means including an avalanche photo-diode, a DC voltage source coupled to said avalanche photo-diode to supply a DC bias voltage thereto, means for superimposing a high frequency voltage on the DC bias voltage to provide beat frequencies between the plurality of optical carrier wave pairs and the high frequency voltage when the optical carrier wave pairs are detected by said avalanche photo-diode; and optical amplifying means optically coupled to said optical combining means.
Claim 23
Dependent Claim 32 words
The system recited in claim 18, wherein: said generating means provides a frequency separation between the two optical carriers within each optical carrier wave pair of up to several tens of GHz.
Claim 24
Dependent Claim 34 words
The system recited in claim 18, wherein: the frequency slots of said assigning means provide a separation between adjacent optical carrier wave pairs on the order of at least 300 GHz to 600 GHz.
Claim 25
Dependent Claim 29 words
The system recited in claim 18, wherein: said generating means includes means for providing a different separation frequency between the two optical carriers within each optical carrier wave pair.
Claim 26
Dependent Claim 28 words
The system recited in claim 18, wherein: said generating means includes a plurality of lasers for generating each of said optical carrier wave pairs independently of one another.
Claim 27
Dependent Claim 52 words
The system recited in claim 22, wherein: said generating means includes a plurality of standing-wave-surface-acoustic-wave transducers operating at different frequencies, said standing-wave-surface-acoustic-wave transducers being positioned relative to said lasers to shift the frequencies of output laser beams from the lasers upwardly and downwardly to provide the plurality of optical carrier wave pairs.
Claim 28
Dependent Claim 19 words
The system recited in claim 18, wherein: said optical carrier wave pairs are used for simultaneous digital information transmission.
Claim 29
Dependent Claim 19 words
The system recited in claim 18, wherein: said optical carrier wave pairs are used for simultaneous analog information transmission.
Claim 30
Dependent Claim 20 words
The system recited in claim 18, wherein: said optical carrier wave pairs are used for simultaneous digital and analog transmission.
Claim 31
Dependent Claim 150 words
A frequency-division-multiplexing system for providing an optical fiber local area network (LAN) with multi-channel transmission of digital and broadband video information, comprising: means for generating a plurality of closely spaced optical carrier wave pairs with the optical carrier waves within each optical carrier wave pair having a predetermined separation frequency between one another; means for assigning each of the plurality of optical carrier wave pairs to a predetermined frequency slot; means for optically combining the plurality of optical carrier wave pairs to provide a multiplexed optical output wave; means for opto-electronic heterodyne detecting the frequency of the optical carrier wave pairs, said opto-electronic heterodyne detecting means including an optical local oscillator for generating local optical carrier wave pairs to provide beat frequencies between the optical carrier wave pairs from said generating means and the local optical carrier wave pairs; and optical amplifying means optically coupled to said optical combining means.
Claim 32
Dependent Claim 150 words
A frequency-division-multiplexing system for providing an optical fiber local area network (LAN) with multi-channel transmission of digital and broadband video information, comprising: means for generating a plurality of closely spaced optical carrier wave pairs with the optical carrier waves within each optical carrier wave pair having a predetermined separation frequency between one another; means for assigning each of the plurality of optical carrier wave pairs to a predetermined frequency slot; means for optically combining the plurality of optical carrier wave pairs to provide a multiplexed optical output wave; means for opto-electronic heterodyne detecting the frequency of the optical carrier wave pairs, said opto-electronic heterodyne detecting means including an optical local oscillator for generating local optical carrier wave pairs to provide beat frequencies between the optical carrier wave pairs from said generating means and the local optical carrier wave pairs; and optical amplifying means optically coupled to said optical combining means.
Claim 33
Dependent Claim 201 words
A frequency-division-multiplexing system for providing an optical fiber local area network (LAN) with multi-channel transmission of digital and broadband video information, comprising: means for generating a plurality of closely spaced optical carrier wave pairs with the frequencies of optical carrier waves within each optical carrier pair having a predetermined separation frequency between one another; said generating means providing a wavelength separation between the two optical carriers within each carrier wave pair of between a fraction of a nanometer up to approximately one nanometer; said generating means including a plurality of lasers for generating each of said optical carrier wave pairs independently of one another; said generating means including means for providing a different frequency separation between the two optical carriers within each optical carrier wave pair; means for assigning each of the plurality of optical carrier wave pairs to a predetermined frequency slot, the frequency slots of said assigning means providing a separation between adjacent optical carrier wave pairs on the order of at least one to two nanometers; means for optically combining the plurality of optical carrier wave pairs to provide a multiplexed optical output wave; and means for opto-electronic heterodyne detecting the frequency of the optical carrier wave pairs.
Claim 34
Dependent Claim 201 words
A frequency-division-multiplexing system for providing an optical fiber local area network (LAN) with multi-channel transmission of digital and broadband video information, comprising: means for generating a plurality of closely spaced optical carrier wave pairs with the frequencies of optical carrier waves within each optical carrier pair having a predetermined separation frequency between one another; said generating means providing a wavelength separation between the two optical carriers within each carrier wave pair of between a fraction of a nanometer up to approximately one nanometer; said generating means including a plurality of lasers for generating each of said optical carrier wave pairs independently of one another; said generating means including means for providing a different frequency separation between the two optical carriers within each optical carrier wave pair; means for assigning each of the plurality of optical carrier wave pairs to a predetermined frequency slot, the frequency slots of said assigning means providing a separation between adjacent optical carrier wave pairs on the order of at least one to two nanometers; means for optically combining the plurality of optical carrier wave pairs to provide a multiplexed optical output wave; and means for opto-electronic heterodyne detecting the frequency of the optical carrier wave pairs.
Claim 35
Dependent Claim 50 words
The system recited in claim 28 wherein: said generating means includes a plurality of standing-wave-surface-acoustic-wave transducers operating at different frequencies, said standing-wave-surface-acoustic-wave transducers being positioned relative to said lasers to shift the output laser beams from the lasers upwardly and downwardly to provide the plurality of optical carrier wave pairs.
Claim 36
Dependent Claim 19 words
The system recited in claim 28, wherein: said optical carrier wave pairs are used for simultaneous digital information transmission.
Claim 37
Dependent Claim 19 words
The system recited in claim 28, wherein: said optical carrier wave pairs are used for simultaneous analog information transmission.
Claim 38
Dependent Claim 21 words
The system recited in claim 28, wherein: said optical carrier wave pairs are used for simultaneous digital and analog information transmission.
Claim 39
Dependent Claim 71 words
The system recited in claim 28, wherein: said opto-electronic heterodyne detecting means includes an avalanche photo-diode, a DC voltage source coupled to said avalanche photo-diode to supply a DC bias voltage thereto, means for superimposing a high frequency voltage on the DC bias voltage to provide beat frequencies between the optical carrier wave pairs and the high frequency voltage when the optical carrier wave pairs are detected by said avalanche photo-diode.
Claim 40
Dependent Claim 45 words
The system recited in claim 28, wherein: said opto-electronic heterodyne detecting means includes an optical local oscillator for generating local optical carrier wave pairs to provide beat frequencies between the optical carrier wave pairs from said generating means and the local optical carrier wave pairs.
Claim 41
Dependent Claim 17 words
The system recited in claim 28, including: optical amplifying means optically coupled to said optical combining means.

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3.5 Years (Year 4) 1991-10-04 1992-04-04 1992-10-04 $2000.00 Window Closed / Lapsed
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